Convertible automobile sound system equalizing

ABSTRACT

A convertible automobile sound system is responsive to the state of the convertible automobile top for providing equlization to speakers related to the state of the convertible top.

[0001] The invention relates in general to convertible automobile soundsystem equalizing, and more particularly concerns novel apparatus andtechniques for adjusting the convertible automobile sound systemequalization in response to the state of the convertible top.

BACKGROUND OF THE INVENTION

[0002] For background, reference is made to U.S. Pat. No. 5,023,914disclosing nonminimum phase equalization of a vehicle sound system, andU.S. application Ser. No. 10/290,989, filed on Nov. 8, 2002, disclosinga dual-mode sound system having optimized modes corresponding todifferent configurational states of an automobile, the entire content ofwhich are incorporated herein by reference.

SUMMARY OF THE INVENTION

[0003] In a convertible automobile, there is a sound system withequalization circuitry. A sensor provides a top state signalrepresentative of the state of the convertible top. The equalizationcircuitry responds to the top state signal to provide equalizationrepresentative of the state of the top. In a specific form of theinvention, the convertible automobile includes left and right dashspeakers, and the equalization circuitry includes left and rightequalization circuitry responsive to the top state signal for providingtop up equalization when the top is up and top down equalization whenthe top is down. The sound system may also include door speakers withdoor speaker equalization circuitry responsive to the top state signalfor providing top up equalization when the top is up and top downequalization when the top is down. The sound system may also includeseat speakers in the seats and seat speaker equalization circuitryresponsive to the top state signal for providing top up equalizationwhen the top is up and top down equalization when the top is down. Thesound system may also include a center dash speaker and center dashspeaker equalization circuitry responsive to the top state signal forproviding top up equalization when the top is up and top downequalization when the top is down.

[0004] Equalization circuitry as used herein means circuitry that coactswith other elements of the sound system so that the radiated acousticpower into the convertible automobile listening area varies as afunction of frequency in a predetermined fashion over a substantialportion of the range of audible frequencies.

[0005] Other features, objects and advantages of the invention willbecome apparent from the following detailed description when read inconnection with the accompanying drawing in which:

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0006]FIG. 1 is a top pictorial view of a convertible automobile soundsystem according to the invention in a convertible automobile in anexemplary embodiment;

[0007]FIG. 2 is a block diagram of a system for providing an audiosignal to energize the sound system of FIG. 1

[0008]FIG. 3 is a graphical representation of the top up and top downequalization furnished by the left and right dash speaker equalizationcircuitry;

[0009]FIG. 4 is a graphical representation of the top up and top downequalization furnished by the center dash speaker equalizationcircuitry;

[0010]FIG. 5 is a graphical representation of the top up and top downequalization furnished by the door speaker equalization circuitry; and

[0011]FIG. 6 is a graphical representation of the top up and top downequalization furnished by the seat speaker equalization circuitry.

DETAILED DESCRIPTION

[0012] With reference now to the drawings, and more particularly FIG. 1,there is shown a pictorial representation of a convertible automobilesound system according to the invention seated in convertible automobile11. There are left, right and center dash speakers 12, 13 and 14,respectively, seated on the convertible automobile dash. There are leftand right door speakers 15 and 16, respectively, mounted to the frontdoors. There are rear speakers including left seat, left channel speaker21, left seat, right channel speaker 22, right seat, left channelspeaker 23, right seat, right channel speaker 24 mounted in or adjacentto the left and right seats 25 and 26. A seven-channel amplifier 31including the equalization circuitry may be mounted under the passengerfloor mat. A sound system control panel 32 may be mounted on the dashabove the center console 33.

[0013] Referring to FIG. 2, there is shown a block diagram illustratingthe logical arrangement of the system for energizing the differentspeakers with seven channels in the exemplary embodiment. There is asignal source 41 that furnishes sound signals to channels 1-7,respectively. Each channel also receives a signal from top state signalsource 42 representative of the state of the convertible top. Channel 1energizes left dash speaker 12 with a front left input signal. Channel 2energizes right dash speaker 13 with front right input signal. Channel 3energizes left door speaker 15 with front left input signal. Channel 4energizes left channel rear speakers 21 and 23 with left rear inputsignal. Channel 5 energizes right channel rear speakers 22 and 24 withrear right input signal. In one embodiment, channels 4 and 5 are leftand right surround channels. Channel 6 energizes right door speaker 16with front right input signal. Channel 7 energizes center dash speaker14 with a mono signal that is half the sum of the left and right frontinput signals.

[0014] Referring to FIG. 3, there is shown the top up equalization 51and top down equalization 52 furnished by channels 1 and 2 to left andright dash speakers 12 and 13, respectively.

[0015] Referring to FIG. 4, there is shown top up equalization 53 andtop down equalization 54 furnished by channels 3 and 6 to left and rightdoor speakers 15 and 16, respectively.

[0016] Referring to FIG. 5, there is shown top up equalization 55 andtop down equalization 56 furnished by channels 4 and 5 to left channelrear speakers 21, 23 and right channel rear speakers 22, 24,respectively.

[0017] Referring to FIG. 6, there is shown top up equalization 61 andtop down equalization 62 furnished by channel 7 to center dash speaker14.

[0018] Preferably, the system is constructed and arranged to furnishminimum phase magnitude equalization for all amplifier/speaker channels,phase alignment equalization using all pass filter stages and/or delaysfor coherent and/or intentional incoherent acoustic energy addition anddelay acoustic energy of rear speakers with respect to front speakers tocreate a front dominant sound stage with an enhanced sense ofspaciousness.

[0019] In practicing the invention, the associated top up mode isgenerally tuned for determining minimum phase magnitude equalization,phase alignment equalization and delay. The top down mode may beestablished by adjusting the magnitude equalization by using thedifference in the speaker raw acoustics between the top down and top upcase. Preferably, there are different delay and polarity relationshipsbetween the front and rear channels in the top down mode to createsimilar spatial and spectral impressions to those obtained in the top upmode. In the top up mode in this example, signals to the rear speakerswere delayed 5 ms with respect to signals to the front speakers, and thepolarity of signals to the rear speakers was reversed with respect tosignals to the front speakers. In the top down mode, the rear signals tothe rear speakers were delayed 6 ms with respect to signals to the frontspeakers, and the polarity of signals to the rear speakers with respectto signals to the front speakers was not reversed.

[0020] This approach can be applied to more complex systems, and is notlimited with respect to which signal processing channel nonminimum phaseproperty is varied with respect to which other channel. In this specificexample, signals to rear speakers were delayed with respect to signalsto front speakers, but other systems may relatively delay signals toother sets of speakers.

[0021] There has been described novel apparatus and techniques for aconvertible automobile sound system. It is evident that those skilled inthe art may now make numerous uses and modifications of and departuresfrom the specific apparatus and techniques herein disclosed withoutdeparting from the inventive concepts. Consequently, the invention is tobe construed as embracing each and every novel feature and novelcombination of features present in or possessed by the apparatus andtechniques herein disclosed and limited only by the spirit and scope ofthe appended claims.

What is claimed is:
 1. A convertible automobile sound system comprising,a plurality of loudspeakers, a source of a top state signalrepresentative of the state of the convertible automobile top,equalization circuitry coupled to said loudspeakers and responsive tosaid top state signal for providing equalization related to the state ofthe convertible top.
 2. A convertible automobile sound system inaccordance with claim 1 wherein said source of a top state signalprovides a top up signal when the convertible automobile top is up and atop down signal when the convertible automobile top is down so that theradiated power by said plurality of loudspeakers as a function offrequency is substantially the same when the top is up as when the topis down.
 3. A convertible automobile sound system in accordance withclaim 2 wherein said plurality of loudspeakers comprise left, right andcenter dash speakers seated on the convertible automobile dash, left andright door speakers mounted in left and right front doors respectivelyof the convertible automobile, left outside, left inside, right insideand right outside seat speakers respectively mounted in left and rightseats of said convertible automobile, a seven-channel amplifierincluding said equalization circuitry, a signal source constructed andarranged to furnish sound signals to the seven channels of saidseven-channel amplifier, the first of said channels constructed andarranged to energize said left dash speaker with a front left inputsignal, the second of said channels constructed and arranged to energizesaid right dash speaker with a front right input signal, the third ofsaid channels constructed and arranged to energize said left doorspeaker with a front left input signal, the fourth of said channelsconstructed and arranged to energize said left seat speakers with rearleft input signal, the fifth of said channels constructed and arrangedto energize said right seat speakers with rear right input signal, thesixth of said channels constructed and arranged to energize said rightdoor speaker with front right input signal, and the seventh of saidchannels constructed and arranged to energize said center dash signalwith a monaural signal that is half the sum of the left and right frontinput signals.